1080i is a DHTV high definition widescreen displaying standard. Commonly pronounced /ten-eighty I/.
1080 means resolution of 1920x1080, i stands for interlaced, which means two fields of half-quality image are being unpercievably rapidly swapped in every frame of such display, in outcome it has half the image quality as opposed to progressive 1080p. As a counsequence of which, framerate is being mentioned in Fields per seconds, that means interlaced displays have half the framerate and sharpness as progressive displays, where famerate is in full Frames per second.